Circuit interrupter



Jan. 20, 1953 J. M. WALLACE ET AL 2,626,329

CIRCUIT INTERRUPTER Filed Dec. 51, 194e 2 SHEETS-SHEET 2 WITNESSES:

ATTOR Y Patented Jan. 2 95 UNITED STATES PATENT OFFICE CIRCUIT IN TERRUPTER Application December 31, 1946, Serial No. 719,524

(Cl. ZOU-89) 2o claims. l

This invention relates generally to electric circuit interrupting devices, and more particularly to such devices having means for controlling the circuit opening and closing times thereof.

In automatic reclosing circuit breakers of the type having separable contacts which are opened electrically in response to overloads on the circuit and are biased to automatically reclose the circuit when the circuit is opened, it has been found desirable to provide for inverse time-current circuit opening characteristics on all operations except the first one or two in any sequence of closely succeeding operations. However, while such breakers are also provided with a time delay in automatically reclosing the circuit, this does not vary with current but is a constant time on every reclosing operation. Since most faults clear themselves on the rst operation of such a breaker, the number of outages of devices demanding continuous energization such as clocks and the like, can be greatly reduced if the time for the rst closing operation of such breakers can be greatly reduced.

Accordingly, one particular object of this invention is to provide in a circuit breaker of the type described, novel means for varying the circuit opening and closing times thereof.

Another object of this invention is to provide in a device of the type described novel dashpot means for controlling the opening times of the breaker so that the initial opening in any sequence of closely successive circuit opening operations will occur relatively rapidly while later openings in any such sequence will be delayed.

Another object of this invention is to provide a novel dashpot structure ror delaying the circuit opening and closing operations of a circuit breaker of the type described so that actual opening and closing of the breaker contacts occur relatively rapidly.

Another object of this invention is to provide in acircuit breaker of the type described, a novel cooperative arrangement of means for counting only closely succeeding circuit opening operations of the breaker with a time delay means for determining the circuit opening and closing times of the breaker, so that such times are variable dependent on the position of the counting means.

These and other objects of this invention will become more apparent upon consideration of the following detailed description of a preferredfem- 2 bodiment thereof, when taken in connection with the attached drawings, in which:

Figure 1 is a substantially central vertical section view of a circuit breaker constructed in accordance with this invention,

Fig. 2 is a partial enlarged elevation view of the breaker shown in Fig. l, and

Fig. 3 is an enlarged transverse section view of the breaker shown in Fig. 1, taken substantially on the line III-III of Fig. 1

The breaker shown on the drawings is illustrated as being mounted in a metal tank 2 having a closed bottom wall and an open top. Preferably, the tank is adapted to be lined at least over the bottom Wall and up to a point adjacent the open top of the container with a liner 3 of insulating material such as liber, or the like, and is adapted to be lled with an insulating liquid, preferably a liquid having arc extinguishing ability, such as foil or the like. The upper end of tank 2 is provided with an outwardly extending flange 4 on which the flange 3 of a cover casting 6 is adapted to be seated, preferably, with a gasket I8 interposed therebetween. Flange 8 of cover casting 6 =1nay be provided with an integral lip l2, and the cover may be secured to the tank in any desired manner, such for example, as by bolts (not shown) extending through openings in cover flange 8 and secured to suitably formed brackets on the tank.

` The breaker contacts and certain of the contact actuating mechanism are adapted to be supported in tank 2 from cover casting 6 by means of a pair of integral supporting lugs i6 depending from the top wall of the cover casting and adapted to en- I gage spacer rods I8 of insulating material having threaded openings at each end for receiving studs I9 extending from supporting lugs I6 and a supporting casting 26. A supporting plate 22 may be supported in a similar manner from casting 20,

so that a solenoid coil 24 may be mounted between casting 20 and supporting plate 22, with the central opening in the coil aligned with openings provided in casting 2i! and plate 22.

lSpa-ced stationary contacts 26 of the breaker are each supported from plate 22 by a support 28 of insulating material, such as ber, formed of inverted U-shape, with the stationary contacts being mounted in openings provided Vin the base portions 38 of each support 28, and with the upper ends of each support 28 having laterally extending flanges 32 by means of which each support is secured t supporting plate 22. As illustrated, each Contact 26 is formed as the head of a bolt to Which a conductor may be secured, as by the nuts 34.

Stationary contacts 26 are adapted to be closed by engagement therewith of a bridging contact 36 having contact tips 38 at opposite ends thereof for engagement with the stationary contacts, respectively. Bridging contact 3B is supported substantially centrally thereof on a slidable contact actuating rod 44 by a pivot pin 40 for limited pivotal movement about a transverse axis. Contact rod 44 being mounted for longitudinal sliding movement through coil 24 and the aligned openings in plate 22 and casting 20, it will be observed that bridging contact 36 is free to adjust itself to the stationary contacts by restricted pivotal movement about its pivotal mounting 40. Contact rod 44 should be of an insulating material such as ber or a molded insulating material.

The upper end of contact actuating rod 44 has a pair of connecting links 45 positioned at each side thereof and pivoted thereon as by a pivot pin 48, with the upper ends of `these connecting links mounted on a common pivot pin 50 for a pair of toggle levers 52 and 54. Toggle levers 52 and 54 are both formed of sheet material, with lever 54 being bent to substantially channel form with outwardly extending flanges 56 adapted to be received at the free end thereof in recesses 58 provided in the spaced downwardly depending ngers of an angled supporting bracket 60 which, in turn, is secured as by a screw E4 to a lug 62 integral with the cover casting. Preferably, the base of the channel part of toggle lever 54 is extended as at 65 through the space between the supporting fingers of bracket S0, and at the other end of lever 54 the sides of the channel formation thereof are extended to be mounted on pivot pin 50. A coil tension spring 68 has one end hooked into an opening 'l0 provided in toggle lever 52, and has the opposite end thereof hooked over an integral spring support (not shown) on the cover casting.

It will be observed that in the closed circuit position of the breaker illustrated on the drawings in full lines, the line of action of toggle spring 68 is below the pivot supporting recesses 58 for toggle lever 54, and accordingly, the toggle spring acts to bias bridging contact 3S into engagement with stationary contacts 26 of the breaker, under a predetermined pressure. However, as soon as contact operating rod 44 moves upwardly to separate the bridging contact from the fixed contacts of the breaker, toggle lever 54 will pivot about recesses 58 and the line of action of toggle .sp-ring 68 will thus be caused to approach that pivot point so that in response to a very small contact separation the line of action of toggle spring 68 will pass through pivot recesses 58 which is the oncenter. position of the resilient toggle arrangement comprising toggle levers 52 and 54 and toggle spring 58. As a practical matter, the opening movement of the contacts necessary to move toggle levers 52 and 54 to the on-center position mentioned above may be made very small, in one operative device being on the order of one-quarter of an inch. When toggle levers 52 and 54 reach their on-center position referred to above. further relative movement of the two toggle levers in the same direction is prevented because the upper edge of toggle lever 52 engages the base of the central channel formation of toggle lever 54. Moreover, since the point at which toggle, spring 68 is hooked into opening TB of lever 52 then substantially coincides with recesses 58 in which toggle lever 54 pivots during contact opening movement, it will be apparent that the remainder and major part of contact opening movement will occur substantially uninfluenced by toggle spring 68. Substantially the reverse of the above operation occurs when contact operating rod 44 .moves downwardly to close the circuit from the full open Contact position, because during the iirst and major part of contact closing movement levers 52 and 54 will be in engagement so that such movement will be uninuenced by toggle spring E8. However, as soon as pivot 58 passes below a line drawn from the remote end of toggle spring 68 through pivot recesses 5S for link 54, toggle spring 68 will then be effective to move 'the toggle levers toward the full line position shown in Figs. 1 and 3, and the force exerted by toggle spring 58 thus tending to close the contacts will continue to increase as toggle levers 52 and 54 move further away from their on-center positions.

Solenoid coil 24 previously mentioned is adapted to be energized under certain conditions for automatically opening the circuit breaker contacts. The central opening through coil 24 preferably is provided with a cylindrical sleeve 'Z4 in which a solenoid core 'F5 is adapted to be slidably mounted in a piston-like manner. Core I6 is in the form of a cylindrical sleeve having Opposed slots 'i8 in the upper portions thereof adapted in the normal closed circuit position of the device illustrated in Fig. l to extend partly above and partly below supporting plate 22, by engagement of an exterior shoulder adjacent the upper end of the core with a sleeve 8i? which has an external rib held between the sleeve 'i4 for the coil and supporting plate 22. The lower end of core 'I6 is provided with opposed holes 8|, for a purpose to be hereinafter described.

A contact actuating sleeve 82 is telescoped over Contact actuating rod 44 and its lower end is received in core 'IS and threadably mounted therein. A coil compression spring 86 is provided within actuating sleeve 82 on contact actuating rod 44 and is adapted to react between an inner shoulder in the core and a pin 88 extending transversely through actuating rod 44.

The circuit through the circuit breaker thus far described may now be traced from the point where it enters tank 2 through one of a pair of terminal bushings 90 (only one being shown), with each bushing secured to cover casting 6 as by bolts 94, and each being provided with a terminal fixture 92 at the upper end thereof mounted on a conductor element which extends through the bushing and emerges from a reduced extension 98 of the bushing seated in an opening provided in the top wall of cover casting G, and proceeds by conductor 98 directly to one xed contact 26 of the breaker. When the contacts are in engagement, the circuit then proceeds through bridging contact 36 to the other fix-ed contact 26, and then by way of a conductor llJ to one terminal of solenoid coil 24. The other terminal of coil 24 is adapted to be connected by a conductor l 02 to the conducting means in the other terminal bushing 90. It will be apparent that solenoid coil 24 in this embodiment of the invention is connected in series in the circuit through the circuit breaker so as to be energized at all times dependent upon the value of the load current flowing in the circuit.

For any given rating of circuit breaker, s-olenoid coil 24 is designed to become suciently energized when the load current'in the vcircuitexceeds its rating as to attract core 16 and move it upwardly. Assuming the upper end of sleeve 14 to be closed except for the small clearance between sleeve 82 and casting 26, so that substantially no iiuid can escape, core 16 will move upwardly relatively rapidly until the bottom of slots 18 reaches sleeve 88, whereupon there is no longer any vent for iiuid contained in cylindrical sleeve 14, and it then becomes necessary upon further upward movement of core 16 to displace the liquid in sleeve 14 above the core through the relatively small clearance between the core and sleeves 14 and 80 and between sleeve 82 and casting 20. Accordingly, opening movement of the core will be slowed up by the aforesaid dashpot action an amount determined by the current value of the overload, and, therefore, an inverse time-current characteristic on opening is obtained. This is due to the fact that the force exerted on core 16 by coil 24 will vary substantially directly in accordance with the value of overload current, and consequently the greater force exerted on higher currents will result in less time delay than on lower values of overload currents. Finally, when the upper ends of holes 8| clear the upper edge of sleeve 8i), core 16 will no longer be restrained by the dashpot action because fluid may then relatively freely escape through holes 8| and the clearance space between the core 16 and rod 44, and the final opening movement thereof may be relativeiy rapid. As soon as core 16 commences its upward travel, bridging contact 36 being held engaged by toggle spring 68 does not move, so that spring 86 is compressed until the energy stored in spring 86 is sumcient to overcome the force exerted by toggle spring 68, at which time contact actuating rod 44 will start to move upwardly. As soon as actuating rod 44 moves upwardly, the force exerted by toggle spring 68 begins to decrease and in a very short distance has substantially no value at all, so that the remaining maior part of the circuit opening movement of bridging contact 36 is easily effected by expansion of spring 86. However, flange 89 is provided to obtain a positive contact separation in the event there is any sticking or welding of the bridging contact to stationary contacts 26. In either case, it is apparent that toggle levers 52 and 54 will be moved to their on-center position in the manner previously described. and bridging contact 36 will be moved by spring B6 to its full open circuit po sition. When the contacts separate and an are is struck, with the resultant pressure developed thereby in the region beneath core 16, it will be observed that washer 42 will be moved upwardly to seat on the lower end of core 16 to close off the clearance space between core 16 and rod 44 and thus prevent gases and other contaminating elements developed by the arc from entering dashpot sleeve 14.

When the breaker contacts have attained their full open circuit position, the parts associated therewith are biased to return by gravity. This closing bias is relatively light and will be immediately opposed bv the dashpot action of core 16. because washer 42 on rod 44 acts as a check valve resting on the lower end of core 16 to close the lower end of the clearance space between the core and rod 44. Accordingly, the return movement will be relatively slow until pivot point 56 moves below the line of action of toggle spring 68 when toggle levers 52 and 54 are in engagement` whereupon bridging contact 36 will be rapidly moved to effect a snap-'action closing of 6 the breaker contacts by toggle spring 68. Moreover, at about this same time the lower ends of slots 18 in core 16 will clear the lower edge of sleeve 80 so as to vent the dashpot comprising sleeve 14 and core 16.

In order to provide means for maintaining the breaker contacts separated and to also provide for manual operation thereof, spring means are provided for holding the breaker contacts open, which means can be manually actuated. This means comprises a toggle lever |04 having a slot |06 at one end thereof for receiving a pin |68 mounted between spaced supporting arms |0 integral with cover casting 6. The other end of toggle lever |64 is pivoted, as by a pivot pin H2, to the adjacent end of a second toggle lever H4, and this, in turn, is mounted yon a pivot pin ||6 intermediate its ends, with the pin ||6 mounted on the adjacent Wall of cover casting 6. A slot |26 is provided through the cover casting 6 forV receiving the other end of toggle lever |4 which acts as a manual operating handle at the exterior of the circuit breaker casing, being provided wth a hook eye |22 in its outer end. A coil compression spring |24 is mounted on toggle lever |84 and reacts between washers mounted on the toggle lever, one of which engages supporting pin |68, and the other of which engages a shoulder located adjacent pivot 2. toggle levers |84 and ||4 are held with pivot ||2 below the center line connecting pins |68 and |6, with the outer end of lever H4 positioned in and beneath an integral hood |25 on cover casting 6, in engagement with an adjustable stop screw |28 mounted in the hood.

In the position of toggle levers |84 and H4 illustrated, they have no effect `on operation of the circuit breaker as previously described, being normally inactive in this respect. However, the common pivot pin ||2 of toggle levers |84 and ||4 is extended at one side toward toggle levers 52 and 54 and in the normal position of the parts extends beneath the adjacent flange 56 of toggle lever 54. Accordingly, if it is desired to manually op-en the circuit breaker contacts, a hook stick or similar operating member may be inserted in hook eye i 22 of toggle lever I i4 and pulled downwardly to rotate the toggle lever in a counterclockwise direction about its supporting pivot I6 to move toggle levers m4 and I4 over center in an upward direction, and in doing this, the common pivot pin ||2 engages the adjacent ange 56 of toggle lever 54 and moves it upwardly in a counterclockwise direction, thus carrying contact actuating rod 44 with it to separate bridging contact 36 from stationary contacts 26. The contacts will be held open by spring |24 which maintains toggle levers |64 and ||4 in their upper overcenter position. In thus manually opening the circuit after toggle spring 63 is moved to its on-center position, it will be observed that the spring |24 of toggle lever |04 is only required to maintain the contacts of the closed only by manual operation of toggle lever ||4 in the opposite direction, that is, byexerting Normally,

an upward force on the ,outer end ofthe. toggle lever to rotate lit in a clockwise direction to move it and toggle lever |04 back overcenter to the full line position illustrated in the drawings, This manual operation of toggle lever ||4 Vdoes not directly close the breaker contacts but merely permits closure of the contacts in the manner previously described, that is, initial closing movement of the contacts being -due to the bias of gravity until bridging contact 35 is closely adjacent stationary contacts 26 when toggle spring 68 is moved below its on-center position and suddenly becomes effective to finally move the contacts into engagement rapidly.

An integrating mechanism for automatically moving toggle levers |84 and ||4 upwardly over center and thus preventing reclosure of the cir- Y cuit breaker yonly in response to a predetermined number of closely successive circuit interrupting operations, and at the same time for automatically controlling the circuit opening and closing times in a predetermined manner in any sequence of a plurality of closely successive circuit opening operations, is provided comprising a cylindrical tube |30 clamped in a split lateral extension |15 of casting 2B at the top of solenoid coil 24 by a screw |11, and this tube has a plug |32 threaded into the lower end thereof with the plug having a small central opening controlled by a ball-check valve |34, which permits ow o1" fluid into the lower end of tube |30 but prevents outflow. An integrating piston |35 is mounted in tube |33 and normally rests on the upper end of plug |32, being provided with a reduced extension |33 at the upper end thereof, having a plurality of spaced circular anges |4B forming rack teeth thereon, and having an elongated insulating extension |42 on the extreme outer end thereof which is positioned below an extension |43 on toggle lever |04. A pawl lever |44 is pivotally mounted at one end as at |45, this end of pawl lever |44 being split with legs located at each side of tube |36 and with pivot |46 supported on spaced supporting flanges integral. with casting 2i).

Pawl lever |44 has a connecting web intermediate its ends, and at the other end thereof the sides of the lever are extended outwardly and laterally as at |48, to normally be in engagement with a washer |56 mounted on actuating sleeve 82 in engagement with a shoulder adjacent the outer end of this sleeve. Pawl lever |44 is normally biased into engagement with washer |50 by a coil tension spring |52 hooked over the remote edge of the web of the pawl lever at one end and anchored to an ear integral with casting 20 at its other end. Pawl lever |44 is provided with a pawl member |54 pivoted thereon as at |5, and biased by a spring |58 in a counterclockwise direction to a, position wherein a portion of pawl member |54 engages the connecting web of pawl lever |44 In order to control the opening and closing times of the circuit breaker contacts to provide for different opening and closing times on predetermined circuit opening and closing operations in any sequence of closely successive operations, as on continuing overloads, the dashpot formed by sleeve 14 and solenoid core 16 has a vent |14 at the upper end thereof which is annular in form `being provided in casting 2|) about actuating sleeve 82. Annular vent |14 communicates with la laterally extending passage |15 also formed in casting 29, so that fluid may escape from the upper end of sleeve 14 through annular vent |14 and passage I 16,l and. thenthroueh a pair of 0pposed openings |18 intube |30 fromwhence it.

may escape through a discharge opening |80, also formed in casing 2li.v The openings |18 in integrator tube 4|30 are aligned with passage |16 and discharge opening |80. Preferably passage |16 is providedwith ,athreaded opening adapted to receive threaded plug |8| having a restricted open` ing |83 (Fig. 2) controlled by a ball check valve |19 to decrease the resistance of the vdashpot formed by sleeve 14 and core 16 so that the delay on closing under the :influence of the relatively light reclosing bias is not unduly long.

With the parts of the circuit breaker at their 14 above the core may be freely-vented through,

the vent passages mentionedV above and consequently the initial circuit opening operation of the rbreaker will occur substantially instantaneously. As solenoid core 16 moves upwardly, washer |50 will be carried upwardly with actuating sleeve |32Y and thus carry the free end of pawl lever |44 upwardly with it to move pawl member |54 into engagement with the upper one of flanges |40 on integrating piston |35, to thus carry the piston upwardly a predetermined distance throughout opening movement of sleeve 82, and due to interlocking ofthe pawl lever and flange |40, no overtravel of piston |36 is possible. Integrating piston |36is not, however, carried upwardly a distance sufcient to entirely remove reduced portion |33 thereof from between openings |18 in cylinder |30, so that the vent passageway from the upper end of dashpot cylinder 14 will not be blocked off by integrating piston |36. When the breaker recloses following such a first circuit interrupting operation, such reclosure will also occur extremely rapidly because core 16 does not have any dashpot action in its dashpot sleeve 14 due to the upper vent for the sleeve still being open. Accordingly, the rst opening and reclosfing of the circuit breaker contacts will both occur substantially instantaneously with no time delay interposed due to thel dashpot action or core 16 in dashpot sleeve 14. During reclosing of the breaker the rst time, integrating piston |36 is left at the position to which it was advanced,

since pawl member |54 is ,free to disengage the circular flanges |40, `and if the breaker remains closed, integrator piston |36 will slowly reset to the position shown in Figs. 1 and 2 this resetting movement being relatively slow due to the necessity of displacing liquid drawn into4 the lower end of cylinder |36 by advancement of piston |36 during the opening operation, past the relatively small clearance between cylinder |30 and piston |36.. This means, of course, that if an overload.

appears on the circuit at a later time, the breaker conta-cts will then be substantially instantaneous- However,v if the breaker immediately rei cylinder 14. Inasmuch as the integrator piston |36 does not closethe vent passage until core 16 is substantially at the end of its circuit opening movement at which time the core vents dashpot sleeve 14, this second closely successive circuit opening operation will, like the first, occur substantially instantaneously with substantially no delay due to dashpot cylinder 14 and core 16. However, on the succeeding reclosing operation, integrator piston |36 having closed the vent at the top of dashpot cylinder 14, this reclosing operation will .be delayed in the manner previously described bythe dashpot action of core 16 in cylinder 14.

During such a second closely successive circuit closing operation, check valve |19 will unseat to permit flow of liquid into passage |76 through opening |83. However, as previously mentioned, opening |83 is relatively small, being provided merely to decrease the time delay due to the dashpot action of core '|6 in cylinder '|4 on closing to the desired amount. Dependent upon the strength of the contact closing bias and the amount of time delay desired, opening |83 may Vary in size or may be omitted entirely. This second reclosing operation will result in leaving piston |36 at the further advanced position described above, from which it eventually will reset in the manner previously described if the breaker remains closed, So that an overload appearing on the circuit at a later time will result in the breaker operating in the manner described above for the rst and second closely succeeding circuit opening and closing operation. However, in the event the overload continues after the second closely succeeding circuit opening and closing operations, the breaker will again open, and this time the opening operation will be delayed by the dashpot action -of core 16 in dashpot sleeve 14, since integrator piston |36 has not had time to recede from the position to which it was advanced on the second opening operation of this series of closely succeeding circuit opening operations,

where it blocks the vent passage from the upper end of dashpot sleeve 14. A vent opening |3| is preferably provided in cylinder |38 to prevent fluid being forced through the clearance space between piston |36 and cylinder |36 and into the bottom of cylinder |36 beneath piston |36 during a time delay circuit opening operation, and thereby preventing undesired advancement of piston |35 at such time. of the breaker following the third opening will be delayed in the mannerpreviously described, in-

asmuch as such third opening operation results in further advance of integrator piston |36 where it -still blocks'the vent passageway from the upper end of dashpot sleeve 74. The breaker may then continue to open and reclose if the overload continues, with each opening and closing being delayed by the dashpot action of core 16 in dashpot sleeve '|4 until finally pawl member |54 advances integrator piston |36 an amount suflicient to cause the upper extension |42 thereof to engage the extension |43 of toggle lever |64 and move this lever upwardly over center so that toggle spring |24 will maintain the contacts separated in the manner previously described. It is thus apparent that toggle levers |65 and H4 will be automatically moved upwardly over center to maintain the breaker contacts separated only in response to a predetermined number of closely successive circuit opening and closing operations, usually four such operations, however, in the event a lesser number ofclosely successive open- The circuit closing operation ing and closing operations occurs, the integrating mechanism will reset and the breaker contacts will be automatically held open only when the predetermined number of opening and closing operations occurs in close succession. Obviously, after the breaker contacts have been automatically actuated to a position where they are held open by toggle spring |24, they can be reclosed only by manual operation of toggle lever ||4 in the manner previously described.

When the breaker contacts are held open in the manner described above, it will be apparent that integrator piston |36 is held at its uppermost position by pawl lever |44 which is held at its upper position by actuating sleeve 82. Accordingly, when the breaker is manually reclosed, vthe first inrush of currentmay be of a value in excess of the rating of the breaker, but since this current is due mainly to the sum of the starting currents of apparatus connected on the circuit, it will be of short duration and it is not desirable that the breaker should open on such initial high currents. Accordingly, it will be observed that when the breaker is manually closed following automatic operation to be held open, the integrator piston |36 will be at a position where it blocks the vent passage from the upper end of dashpot sleeve 14, so that any attempted opening operation of the breaker will be delayed by the dashpot action of core 16 in dashpot sleeve 74. This delay is long enough to permit thehigh value of starting currents encountered on reclosing the circuit to be dissipated, so that solenoid core 16 will reset before it has moved upwardly far enough to cause the breaker contact to open. Integrator piston |36 will also gradually reset and eventually be restored to the position shown in Fig. 1, so that when an overload comes on the circuit at a later time, it can operate in the manner described above to permit the circuit breaker to open and close the circuit, the same predetermined number of times before the breaker contacts are maintained open, and it will Acontrol the times of predetermined circuit opening and closing operations in any such sequence of closely succeeding opening and closing operations in the same manner. In the preferred sequence of operations leading to the breaker contacts maintained lin open circuit position mentioned above, that is, a sequence of four operations in number, it will be apparent that with the apparatus described above, the first two opening operations will occur substantially instantaneously and the second two opening operations' will .be delayed with an inverse time-current characteristicgdue to the dashpot action of core 16 in dashpot sleeve 14. Moreover, the reclosing times, in anysuch sequence Iof four closely successive opening and closing operations will comprise a first substantially instantaneous closing operation with the remaining circuit closing operations being delayed by the dashpot action of core 16 in dashpot sleeve 14. The only time that the rst circuit opening operation is delayed is when such an operation occurs immediately following manual reclosing of the contacts after they have been automatically held open.

If desired, all of the circuit closing operations may be delayed by the dashpot action of core 'i6 in dashpot sleeve '|4 by inserting threaded plug |82 (Figs. 2 and 3) into the discharge :opening |80 for the vent passage from the upper end of dashpot sleeve 14.

A protective gap device |66 of the expulsion type may be provided to prevent operation of i aezaae 1l -.the breaker on voltage surges, with. the outer .f tube Aof the protective `device mounted inter- `mediate its ends on an extension |68 of support- -ing plate 22 at the underside of solenoid coil 24, beingsecured thereto as by nuts Hl! threaded on .thearrester tube. One terminal |12 of the protective devices may be connected with conductor i100 and one terminal of solenoid coil 24, with the other terminal of the protective device (not *.shown) connected with the other terminal of ...coil 24 and conductor |82. This protective device and its particular manner of mounting and con- :necti'on withthis type of apparatus is more particularly disclosed and claimed in the copend- .-ingapplication of H. L.' Rawlins and J. M. Wallace,` Serial` No. 694,074, on Overvoltage Protec- -tiVe`1Devices, led August'SO, 1946, now Patent 'No.'-2,'550,l24, dated April.24, 1951, and assigned nto'ithe. same assignee as this invention. As'stated .f'above, the purpose of providing a protective device |66 connected in the manner described here- .,in and in the aforesaid copending application is to provide a bypass'for solenoid coil 24 on voltage surges such, for example, as those due to -lightning strokes, which are not overloads on the circuit and consequently, it is not desired 4that'the breaker open on such surges.

FromV the foregoing, it is believed apparent that structure disclosed herein' provides an automatic reclosing circuit breaker of the type having electrical means for causing opening'of the breaker .contacts and having the' contacts biased to auto- .'m'atically reclose vwhen the circuit isv opened, Vwithintegr'ating means operated in a particular manner,`which integrating means'controls the ".ly -providing the first two circuit opening operai Vjtions `in any vsuch sequence to be'substantially .instantaneous with the remaining opening operation delayed, and to provide the rst closing operation to be instantaneous with the remaining closing voperations delayed. This permits an eX- tremely rapid opening of the circuit when a fault Vfirst appears followed by an extremely rapid closing so that if the fault has cleared apparatus onthe circuit which depends upon current continuity will not be disturbed. On the other hand, by providing for subsequent openings and clos- ,ings to be delayed, proper coordination with other .'circuitinterrupting apparatus, such as fuses and other. Vcircuit breakers, is provided. Moreover, l it-is apparentthatthe.integrating means further Y.provides for delaying an attempted/first circuit opening operation occurring Awithin a predetermined time following manual closure of the '..breaker contacts after they have automatically .operated t be held open. This prevents start- .ing current drawn by apparatus connected in the circuit from causing an undesired opening of the circuit.

Our invention compirses the novel integrating -mechanism and the novel manner in which it controls the times for opening and closing the contacts. Certain other features disclosed hereinxare not our invention, the particular toggle "structures and the lost-motion spring arrange- "mentffor opening the contacts comprising the invention of H. L. Rawlins and J. M. Wallace, being disclosed and claimed in their copending l `application Serial No. 719,572 iiled concurrently herewith on Circuit Interrupters; and the particular contact structure and means for extinguish- Ling the arc-drawn `upon separation of the contacts is the invention of J. M.'Wallace and J. Kraft being disclosedand claimed inv their copending application Serial No. 718,942 filed December 28, 1946, now Patent No. 2,575,738, dated November 20, 1951, on Circuit Interrupters.

Having described a preferred embodiment of the invention in -accordance with the Patent Statues, it is desired that this invention be not limited to this Yparticular construction, inasmuch as Vit will be apparent, particularly to persons skilled in this art, that many modications and changes may `be made inthis particular-structure without departing from the broad spirit and scope of this invention. Moreover, it `will be readilyappreciated` that`the particular contact gspring arrangements for opening the contacts as well as theV particular contact arrangement and accessories disclosedv herein are merely illustrative, and that the integrating mechanism and novel manner by which it controls the times for opening and closing the breaker contacts may be used with any other desired type of contact actuating mechanism or contact structures, with or without the accessories, such as protective device, counter and the like, herein illustrated, or with different accessories, all withinthe purview of this invention.

Weclaim as our invention:

l. An automatic reclosing circuit breaker comprising, separable contacts,'means having a movable part for causing separation of said contacts to interrupt the circuit in response to a `predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part beingV movable relativeto-said contacts .a predetermined amount before causing contact separation, dashpot means :for delaying movement of said part in lboth directionssaid dashpot means having means for restricting the flow of fluid therefrom throughout the major portion of the movement of said part and means responsive to movement of saidy part for always venting said dashpot means only when said part arrives at points adjacent to but in advance of the ends of its movement in both directions, whereby the major part of the movement of said part in both directions is delayed by said dashpot-means but the final part of its movement is not delayed and occurs relatively rapidly.

2. An automatic .reclosing circuit breaker comprising, separable contacts, solenoid means having a movable core for causing separation of said contacts to. interruptthe-.circuit in response to a predeterminedcirCuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said core being movable relative to said contacts a predetermined amount before causing contact separation, dashpotV means for delaying movement of said core' in both directions, said dashpot means having means for restricting the flow of iiuid therefrom throughout the major portion of the movement of said part and means responsive to movement of'said part for always venting said dashpot means only when said core arrives at points adjacent to but in advance ofthe ends of its movement in both directions, whereby the major part of the movement of said part in both directions is delayed 'by said dashpot means but the final part of its movement is not delayed and occurs relatively rapidly.

3. An automatic reclosing circuit breaker comprising, separable contacts, solenoid means having a movable core for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said core being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said core in both directions comprising a dashpot cylinder in which said core is slidably mounted in a piston-like manner, said dashpot means having means for restricting the flow of fluid therefrom throughout the major portion of the movement of said part and means for always venting said dashpot means at points adjacent to but in advance of the ends of its movement in both directions, whereby the major part of the movement of said part in both directions is delayed by said dashpot means but the iinal part of its movement is not delayed and occurs relatively rapidly.

4. An automatic reclosing circuit breaker comprising, separable contacts, solenoid means having a movable core for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said core being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said core in both directions comprising a dashpot cylinder in which said core is slidably mounted in a piston-like manner, said dashpot means having means for restricting the flow of fluid therefrom throughout the major portion of the movement of said part and means for always venting said dashpot means at points adjacent to but in advance of the ends of movement oi said core in both directions comprising vent passages in said core adjacent each end thereof.

5, An automatic reclosing circuit breaker comprising, separable contacts, means for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, time delay means which is normally ineffective to delay a circuit opening or closing operation of said circuit breaker, and counting means actuated by a part of said breaker which is movable during a circuit opening and succeeding closing operation and prior to reclosing or" the circuit, said counting means having a part associated with said time delay means so as to be responsive only to a predetermined circuit interrupting operation after the first operation in any series of closely successive circuit interrupting operations for rendering said time delay means operative to delay predetermined ones of said circuit opening and closing operations in any such sequence.

6. An automatic reclosing circuit breaker comprising, separable contacts, means for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, normally inactive time delay means, and counting means actuated by a part of said breaker which is movable during a circuit opening and succeeding closing operation and prior to reclosing of the circuit, said counting means having a part associated with said time delay means so as to be responsive to a predetermined circuit interrupting operation after the rst circuit opening and closing operations in any series of closely successive circuit interrrupting operations for rendering said time delay means operative to delay subsequent ones of said circuit opening and closing operations in any such sequence.

'2. An automatic reclosing circuit breaker comprising, separable contacts, means for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, normally inactive time delay means, and counting means actuated by a part of said breaker which is movable during a circuit opening and succeeding closing operation and prior to reclosing of the circuit, said counting means having a part associated with said time delay means so as to be responsive to the second circuit interrrupting operations in any series of closely successive circuit interrupting operations to delay subsequent ones of said circuit opening and closing operations in any such sequence.

8. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, vent means for said dashpot means which is normally open so that said dashpot means is normally inoperative to delay initial circuit opening and closing operations in any sequence of closely successive circuit opening operations, integrating means adapted to be advanced a predetermined amount on each circuit opening operation and being biased to slowly return to a normal position and adapted when advanced a predetermined greater amount due to such an aforesaid sequence of operations to prevent reclosing of said contacts, and valve means for said vent means actuated by said integrating means to close said vent means in response to a succeeding circuit interrupting operation in any such sequence of operations so that subsequent closing and opening operations will be delayed by said dashpot means 9. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, vent means for said dashpot means which is normally open so that said dashpot means is normally inoperative to delay initial circuit opening and closing operations in any sequence of closely successive circuit opening operations, integrating means adapted to be advanced a predetermined amount on each circuit opening operation and being biased to :slowly: return to anormal position and adapted whenuadvanced a predetermined greater amount dueV to such an aforesaid sequence of operations to ',prevent reclosing of said contacts, valve means for "said'vent means actuated by said integrating Ymeans to close said vent means in response to movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting opera-tion, said partbeing movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, vent means for said dashpct means which is normally open so that said dashpot means is normally inoperative to delay initial circuit opening and closing operations in any sequence of closely successive circuit opening operations, integrating means adapted to be advanced a predetermined amount voneach circuit opening operation and being biased to slowly return to a normal position and adapted when advanced a predetermined greater amount due to such an aforesaid sequence of operations to prevent reclosing of said contacts, and valve means for said vent means actuated by said integrating means to close said vent means in response to the second interrupting operation in any such sequence of operations so that subsequent closing and opening operations will be delayed by said dashnot means.

ll. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, vent means for said dashpot means which is normally open so that said dashpot means is normally inoperative to delay at least an initial circuit opening operation in any sequence of closely successive circuit opening operations, integrating means adapted to be advanced a predetermined amount on each circuit opening operation and being biased to slowly return to a normal position and adapted when advanced a predetermined greater amount due to such an aforesaid sequence of operations to prevent reclosing of said contacts, valve means for said vent means actuated by said integrating means to close said vent means in response to an initial circuit interrupting operation in any such sequence of operations so that subsequent closing and opening operations will be delayed by said dashpot means, and additional means for venting said dashpot means at points adjacent to but in advance of the ends of movement in both directions of said movable part so that initial separation and final engagement of said contacts is never delayed by said dashpot means.

12. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the. circuit in response to a Apredetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, vent means for said dashpot means which is normally open so that said dashpot means is normally inoperative to delay at least an initial circuit opening operation in any sequence of closely successive circuit opening operations, integrating means having a normal position, one-way drive means movable with said part adapted to mechanically engage said integrating.` meansv throughout circuit opening movement of said part to advance Asaid integrating means a predetermined amount from its normal position, said integrating means being biased to return to its normal position, means delaying return movement of said integrating means, said integrating means adapted when advanced a predetermined greater amount due to such an aforesaid sequence of operations to prevent reclosing of said contacts, and valve means for said vent means actuated by said integrating means to close said vent means in response to an initial circuit interrupting operation in any such sequence of operations so that subsequent closing and opening operations Will be delayed by said dashpot means.

13. An automatic reclosing circuit breaker comprising, separable contacts, electro-responsive means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit-after a circuit interrupting operation, said part being movablerelative to said contacts a predetermined amount before causing contact separation, integrating means having a normal position, one-way drive means always engaging said movable part so as to be movable with said part throughout circuit opening movement of said part to mechanically engage said integrating means and advance said integrating means a predetermined amount from its normal position, said drive means comprising ratchet means on said integrating means, an actuating lever pivoted at one point and adapted to be actuated at a remote point by said part, pawl means mounted on said lever at an intermediate point whereby said integrating means is advanced on each circuit opening operation a distance less than the travel of said part, said integrating means being biased to return to its normal position independent oi said drive means, means delaying return movement of said integrating means, and said integrating means adapted when advanced a predetermined greater amount due to a predetermined number of closely successive operations of the breaker to prevent reclosing of said contacts.

14. An automatic reclosing circuit breaker comprising, separable contacts, solenoid means having a movable core for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said core being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said core in both directions comprising a dashpot cylinder in which said core is slidably mounted in a piston-like manner, means for venting said dashpot means at points adjacent to but in advance of the ends of movement of said core in both directions comprising vent passages in said core adjacent each end thereof, and check valve means for one of said vent passages to close said passage in response to return movement of said core.

15. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, said dashpot means having means for restricting the 110W of fluid therefrom throughout the major portion of the movement of said part means responsive to contact opening movement of said part for always venting said dashpot means at a point adjacent to but in advance of the en-d of contact opening movement of said part, and separate means for automatically closing said vent means in response to movement of said part in the opposite direction.

16. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, means for venting said dashpot means at a point adjacent to but in advance of the end of contact opening movement of said part, and means for automatically closing said vent means in response to pressure developed by the arc formed when said contacts separate to prevent arc products from entering said dashpot means.

17. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in a contact opening direction, means for venting said dashpot means at a point adjacent to but in advance of the end of contact opening movement of said part, and means for automatically closing said vent means in response to pressure developed by the arc formed when said contacts separate to prevent arc products from entering said dashpot means.

18. An automatic reclosing circuit breaker comprising, separable contacts, means for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, a single time delay means which is normally ineffective to delay a circuit opening or closing operation of said circuit breaker, and counting means actuated by a part of said breaker which is movable during a circuit opening and succeeding closing operation and prior to reclosing of the circuit, said counting means having a part associated with said time delay means so as to be responsive only to a predetermined circuit interrupting operation after the first operation in any series of closely successive circuit interrupting operations for rendering said time delay means operative to delay predetermined ones of said circuit opening and closing operations in any such sequence.

19. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclcse the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying circuit opening movement of said part, vent means for said dashpot means which is normally open so that said dashpot means is normally inoperative to delay at least an initial circuit opening operation in any sequence of closely successive circuit opening operations, integrating means having a normal position, one-way drive means movable with said part adapted to mechanically engage said integrating means to advance said integrating means a predetermined amount from its normal position, said integrating means being biased to return to its normal position, means delaying return movement of said integrating means, said integrating means adapted when advanced a predetermined greater amount due to such an aforesaid sequence of operations to prevent reclosing of said contacts, and valve means for said vent means actuated by said integrating means to close said vent means in response to an initial circuit interrupting operation in any such sequence of operations so that subsequent opening operations will be delayed by said dashpot means.

20. An automatic reclosing circuit breaker comprising, separable contacts, means having a movable part for causing separation of said contacts to interrupt the circuit in response to a predetermined circuit condition, said contacts being biased closed to automatically reclose the circuit after a circuit interrupting operation, said part being movable relative to said contacts a predetermined amount before causing contact separation, dashpot means for delaying movement of said part in both directions, vent means for said dashpot means which is normally open so that said dashpot means is normally inoperative to delay initial circuit opening and closing operations in any sequence of closely successive circuit opening operations, integratng means adapted to be advanced a predetermined amount on each circuit opening operation and being biased to slowly return to a normal position and adapted when advanced a predetermined greater amount due to such an aforesaid Sequence of operations to prevent reclosing of said contacts, valve means for said vent means actuated by said integrating means to close said vent means in response to an initial circuit interrupting operation in any such sequence of operations so that subsequent closing and opening operations will be delayed by said dashpot means, and a removable plug for 19 said vent means adapted when in operative. posi,- ton to always closesad vent means.

JAMES; M. WAI-LAGE. ANDREVRL Wr. EDWARDS. JOSEPH KRAFT:

EEEEEENQES: GAI- TED The fol-lowing references are of reooxd in the le of this patent:

UNrTED STATES PATENTES. l Number Name Date,-

B. Siernlqelg et al: Jan.- 1:,11.8;8;7,

20 H111 Apr. 4', 1893 Thomson Nov. 14:; 1893 Van Valkenburg O ct. 26, 1926 Schweitzer Nov.. 8, 1927 Edsall 12, 1931 MacNeill Aug'. 2., 1938 Grosse May 2, 1939 Thompson May. 4, 1,943 Wallace Nov. 2, 1943 Wallace June. 1, 1948 Kyle, Jr.. et al. July 26; 1949 Van Biyanket al'. Jmly 10; 1951 

